The relationship between pain and associated characteristics of chronic ankle instability: A retrospective study.

Background: Up to 74% of people with a history of ankle sprain develop chronic ankle instability (CAI). One commonly reported residual impairment is ankle pain; however, it has not been included in models or inclusion criteria for CAI. We investigated the prevalence of pain in people with CAI and the association between presence of pain and other CAI characteristics. Methods: Retrospective data from 1147 participants with CAI (age 26.6 ± 10.7 years, 59% female) were collated from previous studies that used the Cumberland Ankle Instability Tool as an assessment tool. Pain was assessed from Item 1 of the Cumberland Ankle Instability Tool, which asks participants about ankle pain. Responses were divided into 3 categories: pain during daily activities, pain during moderate/vigorous physical activities, and no pain. The presence of pain was analyzed with descriptive statistics, the correlation between pain category and CAI characteristics was analyzed by χ2 tests and factors associated with each pain category were analyzed by logistic regression. Results: Among the participants, 60.1% (n = 689) reported ankle pain. Of all participants, 12.4% (n = 142) reported pain during daily activities, 47.7% (n = 547) reported pain during moderate/vigorous physical activities, and 39.9% (n = 458) reported no pain. There was a strong association between ankle instability and ankle pain (χ2 = 122.2, p < 0.001, OR = 5.38, 95% confidence interval (CI): 3.84-7.53). Perceived ankle instability, age and unilateral ankle sprains were independently associated with pain (ankle instability: χ2 = 43.29, p < 0.001; age: χ2 = 30.37, p < 0.001; unilateral ankle sprains: χ2 = 6.25, p < 0.05). There was no significant difference in the presence of pain between genders. Conclusion: The prevalence of pain in people with CAI was high and was related to perceived ankle instability. Number of sprains, age, gender and unilateral or bilateral sprain did not modify this result except for the first pain category (pain during daily activities). There is large gap in current knowledge about the impact of pain in people with CAI, and this topic needs further investigation.